The present invention relates to the cable support arts. It particularly relates to supporting and suspending cables from poles or other overhead support structures, and will be described with particular reference thereto. The invention will also find application in conjunction with various types of cables such as telephone cables, cables for “cable” television, high tension wires, fiber optical cables, and optical ground wires (OPGW's). In addition to suspending cables from poles and the like, the present invention is operative with flat support surfaces and, accordingly finds use in supporting cables and other objects in vault and other similar or related applications.
Power lines, telephone transmission lines, and other cables are frequently suspended aerially from a plurality of poles or other support structures. An aerial cable arrangement is relatively simple and flexible, and has a limited ground footprint that frequently permits space substantially below the suspended cables to be used for other purposes. An aerial arrangement also vertically separates the cables from people or roaming ground animals and reduces the possibility of detrimental contact therewith. Spatial separation is particularly useful for electrical power transmission cables for safety reasons. Aerial suspension of a cable also helps reduce damage caused either inadvertently or through malicious vandalism.
Although aerial cables are relatively safe from ground-based sources of damage, they are subject to environmental wear and damage, principally due to winds. Well known in the art are problems caused by aeolian vibration which is a high frequency, low amplitude vibration caused by laminar winds passing across the line, as well as “galloping” which is a low frequency, high amplitude wind-induced cable motion. Wind action can produce cable damage in the form of abrasion, wear, and fatigue, especially at the suspension points where cable support devices inherently form mechanical stress points in the cable. The potential for such damage can be increased by excessive clamping force, by inadequate clamping force which allows the cable to slide within the clamp, or by an uneven or non-uniform clamping force.
Another issue with pole-mounted cables is efficient arrangement of the various cables. This issue is increasingly confronted due to the rapid proliferation of cable-based transport of electrical power and communication signals. Utility poles typically support cables carrying electrical power, telephone signals, and cable television signals. High-capacity fiber optic cables are being installed in many localities, either for replacing existing electrical signal communication lines or to add additional capacity such as high-speed dedicated Internet access.
Cables sag between the supporting poles, and under the influence of wind the cables can sway about and impinge on one another. Such impingement can damage the cables and also potentially creates safety issues, as for example if a power cable electrically contacts a nearby telephone cable. It is known in the art that a staggered arrangement of the cables, i.e. placing the cables at different heights, reduces the likelihood of damaging impingements.
Yet another area of concern with cable support devices is interchangeability. Cable support installation and maintenance is performed in the field. Cable support devices are typically warehoused at one or more central facilities, for example owned by the utility, and maintenance crews select and bring those selected supports deemed necessary for the various repair jobs to be performed on a given day. Selecting the wrong type of support can delay the installation or maintenance and can create or prolong power or communication outages. The problem becomes more acute during emergency situations such as when there is an immediate need during and after severe thunderstorms, when many critical cables may be damaged at essentially the same time. These problems could be mitigated by a modular cable support system comprising a plurality of adaptable multi-purpose components from which a plurality of different types of cable support devices are constructable.
The present invention contemplates an improved cable support apparatus, method, and system which overcomes the aforementioned problems and others.